Apparatus for timing relay operations



March 20, 1951 BLAIR 2,545,541

APPARATUS FOR TIMING RELAY OPERATIONS Filed Jan. 9, 1948 3 l2 TIME/i 31A v 4/ A 9/ 2:? s2

60 if 23 E5? 7} 54 73 m/vnvrol? Patented Mar. 20, 1951 UNITED STATES PATENT OFFICE APPARATUS FOR TIMING RELAY OPERATIONS Application January 9, 1948, Serial No. 1,387

6 Claims.

This invention relates to electrical circuits for measuring time intervals and more particularly to electronic timing circuits for measuring the time inervals of operations of electrical relays.

It is an object of this invention to provide a new and efiicient electrical timing circuit for measuring the time required for electrical relays to perform their functions.

In accordance with one embodiment of this invention, a timer control circuit includes a triode vacuum tube connected in series with the operating coil of a timer and in series with a gas filled electronic tube together with a power supply for energizing the timer coil and operat ing the tubes. The current through the series circuit of the coil, the vacuum tube and the gas tube is controlled through the operation of the relay under test and its associated contacts. The vacuum tube is first placed in a state in which it will conduct when the gas tube is fired. The normally quiescent gas tube is fired at the start of that part of the relay operation which is to be timed. Firing of the gas tube causes current to flow through the series circuit of the gas tube, the vacuum tube and the timer coil thereby starting the timer. At the end of that part of the operation of the relay which is being timed, the action of the r;1ay applies a block ing bias to the control grid of the vacuum tube cutting ofi the current flow through the series circuit including the coil of the timer thus stopping the timer.

A complete understanding of this invention will be had by reference to the following detailed specification taken in conjunction with the single figure drawing which illustrates diagramatically one embodiment of the invention.

As shown in the drawing, the apparatus is provided with an electronic vacuum tube I and an electronic gas-filled tube II connected in series with an operating or control coil I2 of a timer I3. This series combination is connected through a resistor I4 to a suitable power supply I5 which may be a battery, the negative end of the battery being connected to the cathode I9 of the tube II and the positive end of the battery being connected through the resistor I4 to one end of the coil I2. The tube In is provided with an anode 20, a control grid 2| and a cathode 22, and the tube II is provided with an anode 23, a shield grid 24 and a control grid 25. In the series arrangement, one end of the coil I2 is connected to the anode 2B, and the oath ode 22 is connected to the anode 23. The shield 'grid 24 is tied to the cathode I9.

In case there is a difierence between the start time and the stop time of the timer, a compensating circuit 39 may be provided to make the starting time of the timer conform with the stop time of the timer. The circuit 30 comprises a variable resistor 3| connectable in series with a condenser 32 through a single pole double throw switch 33, which switch also may be operated to discharge the condenser 32 through a shunting resistor 34. The compensating circuit 30 is connected across the tube I0 and the operating coil I2 and in conjunction with resistor I4 has the effect of preventing a sudden current build up in the coil I2. The resistor 3| may be varied to change the current build-up time in the coil, thus to change the starting time of the timer I3.

It will be seen that when both the vacuum tube I0 and the gas tube II are in a conducting state current will flow through the operating coil I2 thereby to start the timer. It will also be apparent that there will be no current flow through the coil I2 if either of the tubes Ill or II is in a non-conducting state. If it is assumed that both tubes are conducting and that current is flowing through the coil I2, a sudden blocking of the tube In by means of a cut on biasing voltage applied to the grid 2| will suddenly cut off the current through the coil I2 and thereby stop the timer.

If the tube II is in a quiescent state and the grid 2| of the tube ID is properly biased, the timer I3 may be started by the firing of the tube II upon application of the proper voltages, and as pointed out before the timer may be stopped by suddenly blocking the tube II In the specific embodiment described herein the tube ID will conduct current when its grid 2| is at the same pot:ntial as its cathode 22 and the tube II has been fired, and the tube I0 may be blocked by applying to its grid 2| a cut off biasing voltage obtained from the negative end of a battery 36 whose positive end is connected to the negative end of the battery I5 and to the cathode IQ of the tube II.

These methods of starting and stopping the timer may be employed to time the various operations of relays having either make or break contacts. To effect the control of the timing circuit by the relay being tested, the control portions of the tubes Ii] and II are connected to a relay 4B under test and its associated contacts 4| through a five pole double throw switch 42;

and a single pole double throw switch 43. The

switch 42 is provided with poles 5|), 5|, 52, 53 and- 54. The poles of the switch 42 are engageable 3 with contacts as follows: pole 55 with contacts 60 and El, pole 5| with contacts 62 and t3, pole 52 with contacts 54 and 55, pole 53 with contacts iii and ii, and pole 54 with contacts "#2 and '13.

When the switch 42 is operated to the left as shown in the drawing, the following circuit connections are made: The negative end of the battery 36 is connected through the contacts 55, the pole 5|] and a resistor l5 to the grid 2| to apply a cut off bias on that grid. At the same time, the grid 2| is also connected to a test terminal 80 to which one of the contacts of the relay under test may be connected, and the cathode 22 is connected through the contacts 12 and pole 54 to a test terminal 8| to which the other contact of the relayunder test may be connected. The resistor allows the negative end of the battery 36 or the cathode 22 to be connected to the grid without shorting the battery 36. The operating coil 82 of the relay 40 under test is connected to two test terminals 83 and 84 which are connectable through switches 85 and 86 to a battery 95 which serves 'to energize the operating coil 82 and also,.as hereinafter described, to apply a blocking voltage to the grid 25. The control grid 25 of the gas tube I is connected to a resistor 9| which is connect able 'by means of switch 43 to either the terminal 83 'or the terminal 84. Resistor 9| should have a relatively high resistance to prevent the gas tube II from altering the characteristics of the relay coil 82 when the coil is connected across portions of the gas tube during the release time tests hereinafter described.

Timing release time of make contacts of a relay All the switches in the circuit are shown in the drawing in a position which prepares the circuit for timing the release time of the make contacts of a relay under test. Such a relay is con nected in the circuit as the relay 45, its operating coil 82 being connected to the test terminals 83 and 84 and its make contacts 4| connected to the test terminals 8|] and 8 I.

In the state in which the apparatus appears in the drawing the tube it is blocked with a high negative bias on the grid 2! thus preventing the tube H from being fired. As soon as the switch 85 is closed, a negative blockin bias is applied to the grid of the tube ii from the battery 95 through switches 85 and 43. At the same time the coil 82 of the relay under test is energized. to close the contacts 4! thereby connecting the grid 2| to the cathode 22 or" the tube it thus preparing the tube ii for current conduction.

After the relay coil 82 has been held energized for a predetermined time, the switch 35 is opened to cut ofi the current through the coil 82. At the same time the negative blocking bias is removed from the grid 25 of the tube H, and the grid 25 being connected to the anode 23 through the switch 43, the coil 82 and the switch 85, it

will be at the same potential as the anode and the tube ll will be fired. This will cause an initially high charging current to flow through the condenser 32 and the resistors 3| and E2, causing an initially high voltage drop to appear across the resistor l4 and correspondingly low initial current to flow through the coil l2 which current will increase as the condenser 32 charges up. As soon as the condenser is charged, the current through the coil i2 will be high enough to start the timer l3.

'-When the relay contacts M are released,they

open the circuit between the cathode 22 and the grid 2| thus permitting the bias voltage from the battery 36 to block the tube ill and cut oil the current through the timer coil i2, thereby stopping the timer l3. Thus it will be seen that the release time of the relay will be indicated on the timer.

Timing the operate time of make contacts of a relay In order to prepare the apparatus for timing, the operate time of the make contacts 4| of the relay 40, the switch 43 is operated to connect the grid 25 to the test terminal 84, the switch 86 is opened and the switch 85 is closed. In addition the five poles 5i], 5!, 52, 53 and 54 of the switch 42 are operated to the right to engage the contacts BI, 63, 65, H and '13, respectively. This connects the negative end of the battery 36 to the test terminal 8|, connects the test terminal 85 to the grid 2| of the tube l0, and connects the resistor 75 betweenthe grid 2| of the cathode 22 of the tube l0.

At this stage it will be seen that the tube ii] is prepared to conduct current since its grid and its cathode are at the same potential. The tube i is blocked because its grid 25 is tied to the negative end of the battery 90 through switch 43, relay coil 82 and the closed switch 85.

The timing test is initiated by closing the switch 86 which simultaneously connects battery Sli to the operating coil 82 of the relay 4E! and connects the grid 25 of the tube H to the anode 23 of the tube ii to fire the'tube Ashore-f inbe fo're described, current will flow through the series circuit of the tubes ill and ll and the coil l 2 thereby starting the timer |3. When the con. tacts 4| close, the negative end of the battery 36" is connected through the switch pole 52, contact 6|, switch pole 54, contact 13 and the rela contacts 4| to the grid 2| of the tube ||l thereby blocking the tube Ill and stopping the timer l3. The indication on the timer will be the operate or make time of the make contacts 4| of the relay 40.

Timing of the operate time of break contacts of a relay To time the operate time of a pair of break contacts 92 of the relay 40, switch 86 must be opened, switch 85 should be closed, switch 43 is operated to connect the grid 25 to the test terminal 82, and the poles 50, 5|, 52, 53 and 54 of the switch 42 are operated to the left as they appear in the drawing. The contacts 4| are disconnected from the terminals and 8|, and the contacts 92 are connected to the terminals 8!! and 8|. With the switches in the positions just described the negative end of the battery 36 will be connected to the grid 2| of the tube it through the resistor 15 and the grid 2| will be tied to the cathode 22 of the tube [I through the closed contacts 92 so that the grid 2| and the cathode 22 will be at the same potential thus readying the tube III to conduct current as soon as the tube H is fired. Tube ii is quiescent because its grid 25 is connected through the switch 43, the relay coil;

82 and the closed switch 85 to the negative endof the battery 95.

To time the operation of the break contacts 92, the switch 85 is closed thereby connecting the positive end of the battery 9!) simultaneously to the relay coil 82 and the grid 25 of the tube H which fires and causes current to flow through the tube I0 and the timer coil |2 to start the" timer l3. As soon as the contacts 92 break open-,

(if the break contacts 92 associated with the relay Timing the release time of break contacts of a relay In order to prepare the circuit to time the release time of break contacts 92, the switch 85 is opened, the switch 86 is closed, the switch 43 is operated upward to connect the grid 25 of the tube II to the test terminal 83 and the switch poles 50, 5|, 52, 53 and 54 of the switch 42 are operated to the right to engage the contacts 6!, 63, 65, II and 13, respectively. With the switch 42 in this position the grid 2| is tied through the resistor 15 to the cathode 22 of the tube It and the grid 2| is connected through the contacts 92 to the negative end of the battery 36 thus locking the tube I 0.

The test is. started by closing switch 85 to simultaneously connect the battery 90 to the op erating coil 82 of the relay 40 and to connect the negative end of the battery 90 to the grid 25 of the tube I I to prevent its firing.

The relay coil 82 being connected to the battery 90, it will be energized to open the break contacts 92 thereby removing the blocking bias of the battery 36 from the grid 2! of the tube I and preparing the tube ill to conduct current. After the relay coil 82 is soaked the switch 85 is opened to disconnect the battery 90 from the relay coil 82 and to remove the negative blocking bias from the grid 25 of the tube I l. lhe grid 25 being connected to the anode 23 through the switch 43, rela coil 82 and the switch 88, the tube II will be fired and will conduct current causing current to flow through the tube IE] and through the timer coil I2 thus starting the timer I3. When the contacts 92 are released they will close to connect the negative end of the battery 35 to the grid 2! of the tube it thereby blocking the current through the tube I d and stopping the timer I3. The timer will then indicate the release time of the break contacts 92.

If'the timer I is of the type that may be m herently compensated or has no differential between its start and stop inertias when connected in the present apparatus, the compensating circuit 30 comprising the resistors SI and I4 and the condenser 32 is not essential to the operation of the apparatus described herein.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. An apparatus for timing relay operations, said apparatus comprising a first electronic tube, a. second electronic tube connected in series with the first tube, each of said tubes having an anodaa control grid and a cathode, the anode of the second tube being coupled to the cathode of the first tube to receive operative anode voltage only through the first tube, a source of unidirectional anode voltage having its positive side coupled to the anode of the first tube and its negative side coupled to the cathode of the second tube, an electric timer control operable to start and stop a timer in response to anode current flow in said tube circuit, a relay with switching contacts controlled thereby, means for energizing the relay, means for applying a blocking bias voltage to the control grid of the second tube when the relay is energized, means for applying a firing voltage to the control grid of the second tube when the relay is deenergized, means coupled to the control grid of the first tube and through said contacts for applying a conducting bias voltage to the control grid of the first tube in response to the operation of said contacts, and

means coupled to the control grid of the first tube and to said contacts for applying a blocking bias voltage to the control grid of the first tube when said contacts are released.

2. An apparatus for timing relay operations, said apparatus comprising an electronic vacuum tube, an electronic gas tube, each of said tubes having an anode, a control grid and a cathode, said tubes being connected in series with each other to receive operative anode voltage only through each other, an electric timer control in series with the anode current path of the vacuum tube and operable to start and stop a timer in response to anode current in said tube, a source of unidirectional anode voltage having its positive side coupled to the anode of the vacuum tube and its negative side coupled to the cathode of the gas tube, a relay with switching contacts controlled thereby, means for energizing the relay, means for applying a blocking bias voltage to the control grid of the gas tube when the relay is energized, means for applying a firing voltage to the control grid of the gas tube when the relay is deenergized, means coupled to the control grid of the vacuum tube through said contacts for applying a conducting bias voltage to the control grid of the vacuum tube in response to the operation of said contacts, and means coupled to. the control grid of the vacuum tube and to said contacts for applying a blocking bias voltage to the control grid of the vacuum tube when said contacts are released.

3. An apparatus for timing relay operations, said apparatus comprising an electronic vacuum tube, an electronic gas tube connected in series with the vacuum tube, each of said tubes having an anode, a control grid and a cathode, the anode of the gas tube being coupled to the cathode of the vacuum tube to receive operative anode voltage only through the vacuum tube, a source of unidirectional anode voltage having its positive side coupled to the anode of the vacuum tube and its negative side coupled to the cathode of the gas tube, an electric timer control operable to start and stop a timer in response to anode current fiow in said tube circuit, a relay with switching contacts controlled thereby, means for energizing the relay, means for applying a blocking bias voltage to the control grid of the gas tube when the relay is energized, means for applying a firing voltage to the control grid of the gas tube when the relay is deenergized, means coupled to the control grid of the vacuum tube through said contacts for applying a conducting bias voltage to the control grid of the vacuum tube in response to the operation of said contacts, and means coupled to the control grid of the vacuum tube and to said contacts for applying a blocking bias voltage to the control grid of the vacuum tube when said contacts are released.

4. An apparatus for timing relay operations, said apparatus comprising an electronic vacuum tube, an electronic gas tube, each of said tubes having an anode, a control grid and a cathode, said tubes being connected in series with each other to receive operative anode voltage only through each other, an electric timer control in series with the anode current path of the vacuum tube and operable to start and stop a timer in response to anode current in said tube, a source of unidirectional anode voltage having its positive side coupled to the anode of the vacuum tube and its negative side coupled to the cathode of the gas tube, a relay with switching contacts controlled thereby, means for energizing the relay, means for applying a blocking bias voltage to the control grid of the gas tube when the relay is deenergized, means for applying a firing voltage to the control grid of the gas tube when the relay is energized, means coupled to said contacts and to the control grid of the vacuum tuberor applying a conducting bias voltage on the control grid of the vacuum tube when the contacts are unoperated, and means coupled to said contacts and to the control grid of the vacuum tube for applying a blocking bias to the control grid of the vacuum tube in response to the operation of the contacts.

5. An apparatus for timing relay operations, said apparatus comprising an electronic vacuum tube, an electronic gas tube connected in series with the vacuum tube, each of said tubes having an anode, a control grid and a cathode, the anode of the gas tube being coupled to the cathode of the Vacuum tube to receive operative anode voltage only through the vacuum tube, a source of unidirectional anode voltage having its positive side coupled to the anode of the vacuum tube and its negative side coupled to the cathode of-the gas tube, an electric timer control operable to start and stop a timer in response to anode current flow in said tube circuit, a relay with switching contacts controlled thereby, means for energizing the relay, means for applying a blocking bias voltage to the control grid of the gas tube when the relay is deenergized, means for applying a firing voltage to the control grid of the gas tube when the relay is energized, means coupled to said contacts and to the control grid of the vacuum tube for applying a conducting bias voltage on the control grid of the vacuum tube when the contacts are unoperated, and means coupled to said contacts and to the control grid of the vacuum tube for applying a blocking bias to the control grid of the vacuum tube in response to the operation of the contacts.

6. An apparatus for timing relay operations, said apparatus comprising a first electronic-tube, a second electronic tube, each of said tubes having an anode, a control grid and a cathode, said tubes being connected in series with each other to receive operative anode voltage only through each other, a source of unidirectional anode voltage connected across said series circuit of the tubes, an electric timer control operable to start and stop a timer in response to anode current flow in said tube circuit, a relay with switching contacts controlled thereby, means for energizing the relay, means for applying a blocking bias voltage to the control grid of the second tube when the relay is deenergized, means for applying a firing voltage to the control grid of the second tube when the relay is energized, means coupled to said contacts and to the control grid of the first tube for applying a conducting bias voltage on the control grid of the first tube when the contacts are unoperated, means coupled to said contacts and to the control grid of the first tube for applying a blocking bias to the control grid of the first tubein response to the operation of the contact, and;

means for controlling the build up of current through said timer control, last said means comprising a resistor-condenser charging circuit connected in parallel with said timer control.

' HAROLD F. BLAIR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

